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Inventar N. PETERS. PHOTD-LITHOGR @geiten grietas atwt @Hire J. Y.SlVIl'lI-I,- OF PII'ISB URG, PENNSYLVANIA. Letters Patent No. 61,043,dated April 23, 1867.

IMPROVEMENT IN STEAM-ENGINE PISTOITS.

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TO ALL WIIOM I'I MAY CONOERN:

Be it known that I, J. Y. SMITH, of Pittsburg, in the countyo'fAllegheny, and State oi' Pennsylvania, have invented certain new anduseful improvements in Metal lackings for Pistons in Engines; and I dohereby declare that the following is a clear, full, and exactdescription thereof, reference being had to 'the accompany ing drawings,making part of this specification, and to the letters Qt' referencemarked thereon, like letters indicating like parts wherever they occur.

Figure l lis a side view; and

Figure 2 is a longitudinal section.

My invention relates to that style of packing in which metallic ringsare used, and where the steam itself acts upon the rings to cause themto packthe piston in the cylinder; and it consists in ya novelconstruction of the rings, and of their arrangement in connection withthe piston-head.

To enable those skilled in the art to construct and use my invention, Iwill proceed to describe it.

`I first construct a piston-head, consisting of the central core Aandthe radial iianges A., these latter being separated by thecircumferential groove or channel a, as represented in the drawings. Itwill be observed that this channel or groove a is made with its sidesinclined, as shown in fig. 2, thereby making the channel wider at itsbottoni than at its outer point. I then construct a niet-al ring, c,which is made wider at its base inside than on its outside, and also aring, e, having its outer surface wider than its inner surface, the.adjoining sides of said 'rings being bevelled or inclined at e.corresponding angle, so that when slipped on the core A their inclinedsides shall fit snugly together, as represented in tig, 1. These ringsare cut through, as represented bythe dotted line i of iig. 1, so as topermit them to yield to the pressure under them, and thus to expand andincrease in diameter, to fill and pack fthe space between thepiston-head and the cylinder.V If desired, these joints z' in thepacking rings may be covered by a piece, t, as represented in iig. 1,this piece being fitted into a suitable recess formed on the side, andalso onithe outer or inner surface of the rings, as may be preferred.Thev rings c and e are made of such a size as to-it loosely upon thecore A, and leave a space between their inner surfaces and the core, asshown in iig. They-are held on the core by the end-plates B, and aremade of such a thiol-:ness as to `just fill, loosely, the space betweenthe inner walls of the plates B andthe flanges A. A series of holes. n,are 'made through the flanges A', as represented in fig. 2, so as tocommunicate between the central groove a and the space under the-packingrings c and e, the arrangement of rings and the liange and plate beingduplicated on each side of the central groove a, as shown inboth figs. 1and 2. The parts being thus arranged, are attached to the piston-rod C,and, altogether, constitute the piston-head and packing, and is theninserted into the cylinder in the. usual manner. l

In operation, the steam which may pass by the rings on o'ne end willenter the groove a, and passing through the holes n will press againstthe inner surface of the rings, thereby distending them and causing themto pack so tightly as to prevent the leakage of any steam 4past the headin the cylinder. .As the ring c presents more surface for the action ofthe steam than e does, it will be expandedmorc than e, and on account oftheir inclined sides, will act as a wedge to forcethe rings outwardagainst the walls of the flange A and plate B, thus packing between themso as to `prevent the escape of any steam from underneath the rings. So,also, as the rings are expanded by -heat, the ring c having more metalto be Aacted upon on its inner surface than e, will thereby be `moreexpanded, and consequently operate in the manner above described.

The groove a may be purposely filled with water, or it may become solled by the condensation of the steam, and still the operation of theparts will be the same, as it is obvious that any steam pre'ssing on thewater 'or other fluid in the groove a will force itV through the holes ninto the space under the rings, :and will press them outward justiuproportion to the pressure applied, and thus'by a very simpleconstruction of parts I am enabled to produce a packing for pistons thatis cheap, durable, and eflicient. It is obvious that the steam whichescapes past the rings into the central groove a will become condensedtherein more or less, and that thus after a littletiine the groove willbecome more or less filled with water, which will serve not only to packor press the rings, instead of steam, but it will also serve as alubricant for the piston. By inserting av cock in the side of thecylinder at any proper point, andmoving the piston so asto bring thegroove a opposite the inner end of the cock or tube, oil or anythersuitable lubricating material may be inserted into said groove forthe purpose of lubricating said piston; and thus I um enabled toaccomplish the twofold purpose of packing and lubricating the piston atthe same time.

Having thus described my invention, what I claim, is-

1. The central groove a, provided with the apertures n, for admittingthe steam or other material to the under side of the rings,substantially as shown and described.

2. The combination of the rings c und e with the anges A and plate B, ortheir equivalents, when arranged and operating afs and for the purposeset forth. i

` J. Y. SMITH. f

'VVitnessesz THos. R. MORGAN, ROBT. W. ROGERS.

